Autoradiographic demonstration of lansoprazole uptake sites in rat antrum and colon

To investigate possible effects of lansoprazole other than its acid suppression through the parietal cell, uptake sites for lansoprazole were studied by autoradiography in rat antral and colon mucosa. Autoradiography was performed using two different methods, i.e., routine fixation and in vitro autoradiography on cryostat sections. Our results showed that the uptake sites for lansoprazole in the gastric antrum were located in the interstitial cells, including unmyelinated nerve fibers, whereas those in the colon mucosa corresponded to epithelial cells and some of the interstitial cells. With electron microscopy, the uptake sites for lansoprazole in the colon epithelial cells were seen exclusively near the apical plasma membrane. On the basis of these findings, lansoprazole may have effects on autonomic nerve and colon epithelial function as well as on acid secretion.